Polyacrylamide Desalting Columns are pre-packed with porous polyacrylamide beads that have either a 2K or a 6/7K molecular-weight cutoff (MWCO) exclusion limit. The three different sizes of pre-packed columns are appropriate for processing samples ranging from 30μL to 2.5mL. The larger columns are designed to desalt biological samples by gravity-flow; the small spin columns (7K MWCO only) are designed for use with a microcentrifuge. Unlike dextran, cellulose and other polysaccharide-based gel-filtration resins, beaded polyacrylamide resin is not subject to enzymatic degradation and will not serve as a nutrient for microbial growth. The resin is very hydrophilic, and this property minimizes the possibility of nonspecific binding and problematic interactions with typical aqueous sample components. Oxidizing agents and hydrazide can be processed without chemical interaction with the support. However, the resin is susceptible to hydrolysis of amide groups when heated under extreme pH conditions. The resin can be autoclaved at near-neutral conditions.